Structure-borne sound isolator and linear actuator with a structure-borne sound isolator

Abstract

Structure-borne sound isolator (100) for reducing structure-borne sound transmission between an actuator and an element driven by the actuator, the structure-borne sound isolator (100) comprising a first isolator (110) and a second isolator (120), - wherein the structure-borne sound isolator (100) is arranged to be positioned outside a housing (10) of the actuator; - wherein the first insulator (110) is arranged to rest against an end plate (14) of the housing (10); - wherein the second insulator (120) is arranged to abut the end plate (14) of the housing (10) and / or one of the side faces of the housing (10); and - wherein the second insulator (120) is arranged in a plane next to the first insulator (110), the plane being parallel to the end plate (14).

Description

[0001] The present disclosure relates to a structure-borne sound isolator and a linear actuator with such a structure-borne sound isolator.

[0002] Electrically adjustable furniture generates structure-borne noise during adjustment due to vibrations. Vibrations in actuators are amplified by the structure of the furniture frame. These mechanical vibrations and the resulting secondary airborne noise are unpleasant for humans. Furthermore, vibrations affect the functionality of the drive systems in electrically adjustable furniture, particularly the collision detection systems of electrically height-adjustable furniture. This can lead to significant limitations and negative impacts on quality and productivity.

[0003] Electrically adjustable furniture systems are just one possible application area for actuators with structure-borne sound isolators.

[0004] One task to be solved is to specify an improved concept for reducing structure-borne noise emissions.

[0005] This task is solved by means of the independent claims. Further developments and refinements are described in the dependent claims.

[0006] The improved concept for structure-borne noise reduction is based on the idea of ​​dynamically decoupling a driven element (e.g., a furniture component) from the driving actuator, thereby reducing the transmission of vibrations and structure-borne noise. This decoupling is achieved by creating a vibrating system directly at the source of the emissions.

[0007] The significance of sound emissions from vibrating surfaces is of great practical importance. The product design of an actuator should take into account the vibration characteristics of the components used. Within the actuator housing, vibrations are generated by components such as the electric motor. In addition to airborne sound, other transmission paths such as cables or connecting elements are also responsible for the acoustic excitation of the actuator housing. Furthermore, structure-borne sound is transmitted to the floor at the installation site via the bearing elements. Vibrations of the floor and connected components can therefore generate noise as a result of the actuator's operation.

[0008] Structure-borne sound isolation refers specifically to the dynamic decoupling of two connected systems, for example, an actuator and a driven element, such as a furniture part or a furniture column. It is usually achieved by placing an elastic element in the transmission path, which can also be called an isolator.

[0009] The hardness of an elastic element is indicated by its Shore hardness. Shore hardness is a numerical value used to determine the hardness of various materials. The higher the number, the harder the tested material. Several scales exist for Shore hardness. The most common are Shore A and Shore D. The scale is usually indicated when specifying the Shore hardness by mentioning the corresponding letter.

[0010] For example, a linear actuator, such as one for installation in an electrically adjustable column of a furniture system, comprises an axially aligned arrangement with a motor assembly and a spindle-nut system. The motor assembly includes an electric motor with a rotating axis or drive shaft, which is mechanically coupled to the spindle-nut system, and a component carrier containing electronics for controlling the motor. The component carrier may also include a communication unit for communicating with other linear actuators and / or with a central control unit. The motor assembly further comprises at least one sensor assembly, which is electrically connected to the component carrier, and a housing, which may, for example, have a cylindrical shape. A first end face of the housing connects to the motor assembly and the spindle-nut system.The motor, the component carrier and at least one sensor arrangement are integrated together within the housing of the motor arrangement.

[0011] The spindle-nut system converts the motor's rotation into linear motion. Optionally, a linear actuator can also include a gearbox. The motor axis and spindle axis can be coaxial, parallel, or at any angle to each other.

[0012] The linear actuator ensures the linear movement of a driven element. For example, the linear actuator can be integrated into a furniture column of an electrically adjustable furniture system. Its application is not limited to electrically powered furniture.

[0013] Referring to the example of an electrically adjustable furniture column, the structure-borne noise isolator is located between the linear actuator and the furniture column in which the linear actuator is installed. The furniture column is the driven element.

[0014] The improved concept is based on the idea of ​​designing a structure-borne sound isolator in two parts and reducing structure-borne sound directly at its point of origin.

[0015] For example, according to the improved concept, a structure-borne sound isolator for reducing structure-borne sound transmission between an actuator and an element driven by the actuator comprises a first isolator and a second isolator.

[0016] The structure-borne sound isolator is configured to be arranged outside the actuator housing. The first isolator is configured to abut an end plate of the housing. The second isolator is configured to abut the end plate of the housing and / or one of the side surfaces of the housing. The second isolator is configured to lie in a plane adjacent to the first isolator, with the plane being parallel to the end plate. For example, both the first and second isolators have an edge or edge surface that abuts the shared plane.

[0017] The primary function of a structure-borne sound isolator is to isolate the vibration of the actuator from the driven element. This primary function is achieved by the first isolator.

[0018] In addition to its primary function, the structure-borne sound insulator fulfills the following secondary functions: The connection between the actuator and the driven element requires torque support, for example, via a bolted connection. These bolts can be a source of structure-borne noise transmission. In particular, bolts can strike the screw holes laterally. The structure-borne noise isolator provides decoupling of the torque support to prevent this.

[0019] For example, the second insulator forms a frame for the first insulator, with the first insulator being arranged within the frame of the second insulator and connected to the second insulator by a force-fit or form-fit connection, or being designed to be attached to the end plate. The inner diameter of the frame of the second insulator can be less than or equal to the diameter of the end plate. In particular, the inner diameter of the frame can be deliberately chosen to be as large as possible, so that, on the one hand, the end plate is covered to the edge or almost to the edge in the edge region, and, on the other hand, slippage of the housing through the second insulator is prevented.

[0020] For example, the first isolator is set up to minimize structure-borne sound transmission between the actuator and the element driven by the actuator.

[0021] The center of gravity of the first insulator is chosen such that, when mounted with the actuator, it lies above a drive shaft of the actuator.

[0022] The first insulator, for example, is made in one piece.

[0023] For actuator installation, the structure-borne noise isolator offers a pre-positioning option, for example, through protrusions on its end face that fit into corresponding recesses in the driven element. The decoupling of the torque support, for instance, forms such a protrusion relative to the rest of the structure-borne noise isolator. This ensures that the actuator is correctly aligned with the driven element during assembly, allowing it to be screwed in place, for example.

[0024] For example, the second insulator has at least one opening for fastening means for attachment between the actuator and the driven element, wherein the at least one opening is surrounded by a decoupling and the decoupling includes at least one of the following functions: structure-borne sound decoupling of the fastening means; a positioning aid for mounting the actuator with the driven element.

[0025] For the sensory detection of a collision, the structure-borne sound isolator, in its various designs, offers a means of controlled introduction of a vibration or force flow to a sensor integrated into the actuator. This introduction may be necessary because the changes in force flow caused by a collision can be reduced to such an extent by the structure-borne sound decoupling effect that collision detection is severely impaired.

[0026] For example, the second isolator has a plunger, and the first isolator has a recess to receive the plunger, in order to selectively transmit vibration from the driven element via the plunger to a sensor array of the actuator without structure-borne noise decoupling. The plunger is positioned, for example, such that when mounted with the actuator, it is located above the actuator's sensor array.

[0027] For example, the second insulator has a locking device designed to create at least one force-fit and / or form-fit connection between the second insulator and the end plate and / or one of the side surfaces of the housing.

[0028] The aforementioned second functions are achieved by the second insulator.

[0029] A key feature of the two-part design is the resulting division of the aforementioned first and second functions between the first and second insulators, and the consequent freedom to choose the optimal material for each. For example, the Shore hardness of the first insulator can be selected independently of the Shore hardness of the second insulator. Furthermore, the first insulator can be taller or thicker than the second insulator.

[0030] This allows, on the one hand, optimal structure-borne sound decoupling through the choice of material for the first insulator and, on the other hand, optimal fulfillment of the second functions through the choice of a different material for the second insulator.

[0031] In various embodiments, either the first or the second insulator includes a cable and / or a connector. Alternatively, the first insulator has a recess for the passage of a cable and / or a connector.

[0032] In various embodiments, the first insulator and the second insulator each consist of an elastic material. The elastic material is, for example, an elastomer, a rubber, a rubber compound, a polyurethane material, a silicone, a foam rubber, or a combination of these materials.

[0033] For example, the elastic material may contain closed or open air chambers. Alternatively, the elastic material can be a solid material.

[0034] A linear actuator of the type described above can be equipped with a structure-borne sound isolator according to one of the described designs. The structure-borne sound isolator is located on the outside of the end plate of the housing.

[0035] Further configurations of the linear actuator result from the described explanations.

[0036] The improved concept is explained in more detail below with various embodiments of the invention, illustrated by drawings. These drawings show, in some cases in a simplified form: Fig. 1 a structure-borne sound isolator with a first and a second isolator; Fig. 2 a second insulator; Fig. 3a a first insulator; Fig. 3b a first insulator with mushroom heads; Fig. 3c another view of a first insulator with mushroom heads; Fig. 4 a mounted structure-borne sound isolator; Fig. 5 a first insulator with integrated cable; Fig. 6 a section through a structure-borne sound insulator; Fig. 7 a furniture column with a structure-borne sound insulator; Fig. 8 a linear actuator with a spindle-nut system; Fig. 9 an exploded view of a linear actuator motor; and Fig. 10 a table with a furniture column with built-in linear actuator.

[0037] The Fig. Figure 1 shows a two-part structure-borne sound insulator 100 comprising a first insulator 110 and a second insulator 120, wherein the first insulator 110 is located next to the second insulator 120.

[0038] In one embodiment, the first insulator 110 lies next to the second insulator 120 in a common plane parallel to an end plate 14 of the housing 10 of the actuator.

[0039] In one configuration, the first insulator 110 is enclosed by the second insulator 120. In other words, the second insulator 120 forms a frame for the first insulator 110. In this configuration, the first insulator 110 can also be referred to as the inner insulator and the second insulator 120 as the outer insulator, since the first insulator is located inside and next to the second insulator.

[0040] The second insulator 120 surrounds the first insulator 110 and forms a force-fit or form-fit connection with the first insulator 110. For example, the first insulator 110 is attached or clamped to the second insulator 120 via a press fit.

[0041] In another embodiment, the first insulator 110 is connected to the end plate 14 of the actuator housing 10 by a force-fit or form-fit connection. For this purpose, the end plate 14 has at least one opening (see Fig. 9, Fig. 240', Fig. 240'') to accommodate, for example, mushroom-shaped extensions (see Fig. 3b and Fig. 3c, Fig. 205', Fig. 205'') on the underside of the first insulator.

[0042] For example, the structure-borne sound isolator 100 has a round shape for a cylindrical actuator housing. Of course, the structure-borne sound actuator can also take on any other shape, especially polygonal ones, such as rectangular or square.

[0043] The first insulator 110 and the second insulator 120 are each made of an elastic material, such as an elastomer, rubber, a rubber compound, a polyurethane, silicone, foam rubber, or a combination of these materials. The elastic material can include closed air chambers, open air chambers, or no air chambers at all (solid material). The elastic material can form a spring-damper system or a spring system. Examples of such materials are Sylodyn®, Sylomer®, or Sylodamp® from Getzner.

[0044] The Fig. Figure 2 shows the second insulator 120 of the structure-borne sound insulator 100. The second insulator 120 has no base. In its rounded form as shown, the second insulator 120 can also be described as ring-shaped.

[0045] For example, in Fig. 4, Fig. 6 and Fig. As shown in Figure 7, the structure-borne sound isolator 100 rests against the end face of a housing 10 of a linear actuator 19 when used as intended. After the actuator is mounted with a driven element, e.g., a furniture column, the structure-borne sound isolator 110 is located between the driven element and the housing 10 of the actuator.

[0046] In one embodiment, the actuator and driven element are connected via at least one fastening element 170', 170'' (see Fig. 7), for example, a screw, connected to each other at the end face. This connection serves to support torque. For this purpose, the structure-borne sound isolator 100 has at least one opening 130', 130'' for each of the fastening elements 170', 170''.

[0047] The fasteners 170', 170'' can be a source of structure-borne noise transmission; in particular, screws can strike the screw holes laterally. The structure-borne noise isolator provides decoupling 135', 135'' of the torque support, or rather of the fasteners 170', 170''. For this purpose, the second isolator has, for example, at least one structure-borne noise-decoupled screw feedthrough 135', 135''. This decoupling surrounds each of the openings 130', 130'' with the elastic material of the second isolator 120.

[0048] Furthermore, the second insulator 120 has one or more locking devices 150', 150'', for example in the form of snaps or detent elements. During assembly, the structure-borne noise insulator 100 is first connected to the housing 10 of an actuator by means of the locking device. Only then is the actuator mounted on the driven element. If, for example, the actuator is transported between the two assembly steps, a locking device 150', 150'' is required to secure the structure-borne noise insulator 100 to the actuator.

[0049] In combination with the at least one opening 130', 130'' for fasteners, the captive fastener 150', 150'' offers a further advantage. In one embodiment, the at least one opening 130', 130'' is surrounded by a decoupling element 135', 135'', for example, a cylindrically shaped decoupling element.

[0050] In one configuration, this decoupling element 135', 135'' protrudes beyond the other elements of the second insulator. Since the second insulator 120 is secured to the actuator by the locking device 150', 150'', the decoupling element 135', 135'' can be used for pre-positioning on the driven element. For example, the actuator with the structure-borne noise isolator mounted is inserted into a furniture column and rotated until the decoupling element fits into a screw hole in the furniture column. This aligns the actuator correctly, and the screws for fastening can be easily inserted.

[0051] The locking mechanism 150', 150'' of the second insulator 120 forms approximately a force-fit and / or form-fit with the housing of the actuator.

[0052] For example, the second insulator 120 is made of elastic material and is placed over the outer surfaces of the housing 10 of the actuator and is held on the actuator by its elasticity and frictional connection.

[0053] For example, the second insulator 120 is made of elastic material and the locking device 150', 150'' has studs which are held in corresponding recesses of the housing 10 by positive locking.

[0054] For example, the second insulator 120 is stretched and placed over the housing 10, causing the studs of the locking device 150', 150'' to penetrate recesses in the housing.

[0055] For example, the studs of the 150', 150'' locking device protrude into the outer side surfaces or the front face of the actuator housing.

[0056] For the sensory detection of a collision, the structure-borne sound isolator 100 offers, in various configurations, a possibility of controlled introduction of a force flow onto a sensor arrangement built into the actuator (see 15 in Fig. 7) This introduction may be necessary because otherwise the vibration caused by the collision, or the resulting force flow, would be reduced to such an extent by the structure-borne sound decoupling effect that collision detection would be severely impaired. To prevent this, the second insulator 120 has a plunger 140.

[0057] In one embodiment, the second insulator 120 has an arm with a punch 140. The arm is also elastic and, for example, made of the same material as the second insulator 120.

[0058] The sensor assembly 15 and the plunger 140 are positioned ideally for the measuring principle to ensure reliable collision detection even under low loads. The plunger 140 introduces the force from a collision into the end face of the actuator housing 10 at the point where it is located and transmits it to the sensor assembly 15.

[0059] For example, the sensor assembly 15 and the stamp 140 are arranged one above the other.

[0060] For example, sensor arrangement 15 and punch 140 are arranged centrally above the drive shaft 1.

[0061] For example, sensor arrangement 15 and punch 140 are arranged off-center next to the drive shaft 1, especially when the sensor arrangement 15 is arranged on a component carrier that surrounds the drive shaft 1.

[0062] The Fig. Figure 3a shows a first insulator 110.

[0063] In one embodiment, the first insulator has 110 recesses 180', 180'' for receiving the decoupling elements 135', 135''.

[0064] In another embodiment, the first insulator 110 has a recess 190 for receiving a connecting cable or a connector plug.

[0065] In another embodiment, the first insulator 110 has a recess 200 for the stamp 140.

[0066] The Fig. 3b and Fig. Figure 3c shows various representations of a first insulator 110 with mushroom-head-like extensions on the underside of the first insulator 110, with which the first insulator is connected to the end plate 14 of the housing of the actuator in a force-fit and form-fit manner.

[0067] The Fig. 4 and Fig. Figure 5 shows two different ways of attaching connecting cables or connectors.

[0068] In the Fig. 4. A connector plug is used, which is guided through the recess 190 for receiving a connecting cable or a connector plug 210. In this case, for acoustic reasons (and also for fire protection reasons, among others), the gap between the cable, plug and the first insulator 110 should be minimized.

[0069] In the Fig. 5. The connector 210 is part of the first insulator 110 and is permanently connected to it, for example, by potting. In this case, there is no gap between the cable, the connector, and the first insulator 110.

[0070] Alternatively (not shown), the connector can also be part of the second insulator 120 and permanently connected to it, for example by potting.

[0071] The Fig. Figure 6 shows a section through the actuator in the area of ​​the end face. The actuator housing 10 is closed and bounded at its end face by an end plate 14. The structure-borne sound insulator 100 rests against the end plate 14 with both its second insulator 120 and its first insulator 110. The plunger 140 of the second insulator 120 also rests against the end plate 14. Furthermore, two openings 130', 130'' for fastening elements are shown in this embodiment.

[0072] The first insulator 110 is attached by means of a press fit between the frame formed by the second insulator 120 and the punch 140 of the second insulator 120.

[0073] For example, in the unloaded situation shown here, the first insulator 110 protrudes above the piston 140. Subsequently, the static weight of a driven part compresses the first insulator 110 to such an extent that the piston 140 and the first insulator 110 reach the same height.

[0074] The inner diameter of the second insulator 120 is chosen to be as large as possible, but less than or equal to the diameter of the end plate of the actuator housing 10. This ensures that the second insulator 120 rests just on the end plate 14 and simultaneously allows for the maximum possible outer diameter of the first insulator 110. The first insulator 110 fills the area surrounded by the second insulator 120, thus maximizing the area used for structure-borne noise decoupling. The actuator vibrations, which are primarily transmitted to the driven element via the end plate 14, are therefore almost completely diverted through the first insulator 110, except for a small remaining contact area of ​​the second insulator 120. This achieves maximum decoupling.

[0075] The center of gravity of the first insulator 110, for example, lies above a drive shaft 1 of the actuator. The resulting force acting on the drive acts on the center of the actuator, thus preventing tilting (buckling) of the actuator.

[0076] The Fig. Figure 7 shows a linear actuator 19, which is installed in a furniture column 18, for example a telescopic furniture column. The combination of linear actuator 19 and furniture column 18 is connected to a furniture frame (not shown), for example a table frame, by means of a mounting plate 220.

[0077] For example, the furniture column 18 comprises two or more nested, telescopically movable tubes.

[0078] The first insulator 110 has a receptacle for the plunger 140 of the second insulator 120. The plunger 140 serves to transmit force to a sensor arrangement 15 located below the plunger 140, for example a sensor located on the end plate 14 of the linear actuator 19, which is, for example, centered above the center point 230 of the drive shaft 1 of the linear actuator 19.

[0079] In another embodiment, the sensor arrangement 15 can also be mounted on a component carrier 12 of the motor control, which is located around the drive shaft 1 (see Fig. 9) In this case, the sensor arrangement 15 is located off-center next to the drive shaft 1 and the piston 140 is also off-center and again mounted above the sensor arrangement 15 on the second insulator 120.

[0080] The structure-borne sound isolator 100 can be adapted to different applications, such as varying weights of the driven parts, by selecting the appropriate material for the first isolator 110. First isolators 110 are easily replaceable.

[0081] The Fig. Figure 8 shows a section through an embodiment of a linear actuator 19 with a spindle-nut system, as described, for example, in DE 102012102298 A1, in which a motor 8 and a gearbox 7 are arranged in a two-piece housing 10, together forming a drive for a spindle system. The spindle system includes, among other things, a drive shaft 1, which is driven by the motor 8 or the gearbox 7. The drive shaft 1 extends longitudinally within a profile tube 2, to which the drive shaft 1 is fixed on its outer side so as to be rotationally fixed and longitudinally displaceable. The spindle system further includes a threaded hollow spindle 3 with an external thread, which is arranged between the drive shaft 1 and the profile tube 2 and is fixedly connected to the drive housing 10. A hollow spindle nut 4 is fixedly connected to the upper end of the profile tube 2 and interacts with the external thread of the threaded hollow spindle 3.At the lower end of the profile tube 2, a spindle nut 6 is fixedly connected to the profile tube 2. Inside the drive shaft 1, a threaded spindle 5 is arranged, which interacts with a thread of the spindle nut 6. The external thread of the threaded hollow spindle 3 and the thread of the threaded spindle 5 have opposite helix directions.

[0082] The Fig. Figure 9 shows an exemplary exploded view of a motor 8. The motor 8 comprises a rotor 11, a stator 9, a component carrier 12, a drive shaft 1, an end plate 14 with a sensor assembly 15 attached to the underside of the end plate 14 (and therefore in the Fig. 9 is concealed) and is electrically connected to the component carrier 12 via a connection 13. The end plate 14 forms an end face of the housing 10.

[0083] The Fig.Figure 10 shows a schematic diagram of an electrically adjustable piece of furniture, in this case a height-adjustable table. The table has a tabletop 16, the height of which can be adjusted via a linear actuator 19. The linear actuator consists of a motor assembly and a conversion mechanism, e.g., a spindle-nut system. The conversion mechanism is designed to convert a rotary motion generated by the motor assembly into a linear deflection or change in length or elongation of the linear actuator. The linear actuator 19 is located in the furniture column 18 and connected to a control unit 17, which allows a user to, for example, input commands for the table to effect a height adjustment.

[0084] The structure-borne sound isolator 100 is located between the linear actuator 19 and the electrically adjustable furniture column 18, which in this example represents the driven element. The furniture column 18 is, for example, part of an electrically adjustable furniture frame on which the tabletop 16 is mounted. Reference symbol list 1 drive shaft 2 profile tubes 3 threaded hollow spindle 4 hollow spindle nuts 5 threaded spindle 6 Spindle nut 7 gearboxes 8 engine 9 Stator 10 cases 11 Rotor 12 component carriers 13 Connection for sensor assembly 14 End plate 15 Sensor arrangement 16 Tabletop 17 Control unit 18 Furniture column 19 Linear actuator 100 structure-borne sound insulators 110 first insulator 120 second insulator 130', 130" opening for fasteners 135', 135" decoupling of the torque support. 140 stamps 150', 150" captive bead 170', 170" Fasteners 180', 180" cutouts for decoupling 190 Recess for connecting cable, plug 200 Exclusion for the stamp 205', 205'' mushroom-shaped extension 210 connector plug 220 Mounting plate 230 Axis / Center of the drive shaft 240', 240'' opening QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102012102298 A1

[0081]

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